Carport deviation from the building application

How far can I deviate from the building application without getting into trouble?

Without an amendment to the building application not at all, unless the changes would be exempt from the procedure. In my assessment, for

Instead of 6.50 meters maybe 6.80 meters

an amendment would be required, for

The slightly slanted one (Wallmartig) should now go straight down.

rather not. As Payday correctly wrote, the first measure would only be approvable if the extension is towards the residential building or if the entire carport is pushed to the boundary.

you can also set the carport with a width of 6.8m to 6.5 meters. simply shorten the crossbeam by 30cm
an amendment at the building authority is not a big deal either.

and normally necessary parking spaces and their coverings are exempt from formal procedures. your architect can also explain and clarify that for you, or you take a look at the building regulations and development plan or call the officer at the authority.
in our case, a carport is also drawn in the application. but without exact size/length/position, etc. for us it is exempt from procedures, just so they already know roughly where the thing will go.

what exactly do you want with the 1 meter to the boundary? hedge? then way too wide and somehow not sensible either. the best thing will be if you coordinate with your neighbors.

The meter is for the future. Someday I have to paint the carport and so I don't have to ask the neighbors.

that's nonsense. you have a "hammerschlagsrecht" to paint your carport from the neighboring property. of course, their property must not be damaged or destroyed in the process. if they plant a hedge there, you can still reasonably access it for repainting or similar. if they put up a carport, the wall is not visible anyway.

......he installs a carport, the wall is not visible anyway......

And happily lazes around.

Procedure-free does not mean that everything is allowed.

Best regards in brief